Daughter of a lady-friend recently purchased a hunk-of-junk 2005 Ford 500 (205 kmile on it I think). Info about this model here (Edmunds). Due to a severely rough running engine, the car is not roadworthy, so I am giving repairs a try myself before resorting to having the car towed to a mechanic (kid does not have $$ for tow or professional repair at this time, yet badly needs transportation in order to keep her current job). The car is parked outside. Terrible weather today. Weather should be MUCH better tomorrow for me to go back and do some more in-depth troubleshooting. In the meantime, I was wondering if some of our knowledgeable folks would be willing to give me some tips on what and how I should pursue the problems when I go back tomorrow. Before I got involved, the owner had a supposed master-mechanic friend look into the issues. Autozone had read the codes before the car became undrivable and I was told that the Autozone worker advised there was a misfire in #3 and #4. With that info, the mechanic replaced all of the spark plugs (heard it was a SERIOUS pain to access the back side). He also replaced the fuel filter. As far as I can tell from talking to the ladies, that is all he did engine performance related. The ladies seemed to think the mechanic friend wanted to go down the faulty coil path next (coil on plug setup), but he has not been back around in a while. I was informed that the engine ran even worse after the â€˜repairs' Using this simple bluetooth code reader(from Amazon), I obtained two codes: P0351 (defective ignition coils, IAC issues, plugs, vac leak, dirty throttle body, etc) P2544 (PCM input issue, torque management request input signal A, and down the rabbit hole we go!). I have not had a chance to poke around under the hood, and only had a short while with the code reader this afternoon, with lots of that time trying to learn how to use its features. I tried to log some data, but I think I failed. May have to try again tomorrow. Here are some observations from memory: 1) Idle is relatively smooth. But, when pushing the throttle to the floor, rpm only goes to upper 2800's with some bumpy missing. Putting the car in gear, holding break, then giving it some gas results in REALLY bad stumbling with almost no power at all. 2) Charting of % throttle position (manifold) data showed ~14% at idle, 20% with the accelerator floored. 20%???? 3) Timing advance moved around from -5 to +5 degrees at idle. Went to +42 degrees at full throttle. 42 degrees???? 4) Charting of 02 sensors showed a rough sine-like wave (several seconds peak-to-peak) on all but bank 2, sensor 2 which held the peak for several extra seconds before going back to zero. 5) Don't know whether it was the data reader or not, but charting fuel pressure resulted in a flat line at bottom of chart. Granted the y-axis auto set itself to a minimum of 70 (that's psig I presume?). So, if pressure was less than 70, it wouldn't show. Didn't know how to re-span the y-axis and didn't spend any time trying. Thoughts?